IS 15130 (Part 3): 2002 :2000 iSO 6974=3 Ic&lri* $FH-$FTf w-J13ahm-Qihlmimw?a' 5qmqih-% m~)m, mdd "w-s@wwT:G ~~ Cfj ii~ ~i~$$ i$mr'w , @fmfkmI WP$nn71w+ Indian Standard NATURAL GAS -- DETERMINATION OF COMPOSITION WITH DEFINED UNCERTAINTY BY GAS CHROMATOGRAPHY PART 3 DETERMINATION AND OF HYDROGEN, HELNAVI, DKIXIDE HYDROCARBONS UP TO C8 USING OXYGEN, NITROGEN, CARBON TWO PACKED COLUMNS I(X3 75.060 @ E31s2002 BUREAU MANAK OF BHAVAN, IN DIANSTA ND ZAFAR ARDS MARG 9 BAHADUR SHAH NEW DELHI 110002 April 2002 Price Group 7 Natural Gas Sectional CommiHee, PCD 24 NATIONAL FOREWORD This Indian Standard (Part 3) which is identical with ISO 6974-3:2000 `Natural gas -- Determination of eamposJ\iun with defined uncertainty by gas chromatography -- Part 3: Determination of hydrogen, helium, oxygen, nitrogen, carbon dioxide and hydrocarbons up to C8 wing two packed columns' issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of the Natural Gas Sectional Cammittee and approval of the FWchm, Coal and Related Products Division Council, The text of 1S0 Standard has been proposed to be approved as suitable for publication as Indian Standard without deviations. Certain conventions are, however, not identical to those used in Indian S!andards. Attention is particularly drawn to the following: a) b) Wherever the words `international be road as `Indian Standard'. Standard' appear referring to this standard, they should the current Comma (,) has been used as a decimal marker while in indian Standards, practice is to use a point (.) as the decimal marker. In this adopted standard, reference appears to the following International Standards for which Indian Si8~d~~d~ MSO wist. The ~O~~esp~nding Indian Skmdwds, which are to be substituted in their place, for the editions indicated, However, that We @Jen below along with their degree d ecphdenm In\erna\ional Standard cross referred in this adopted 1S0 Standard which has subsequently been revised, position in respect of latest 1S0 Standard has b~en given: lntt?mathmi CWqxmihg standard indhm Standard IS 15130 (Part 1) :2002 Natural gas-- Determination of composition with defined Lmcwtainty by gas chrurnatugraphy: Part 1 Guidelines for tailored analysis 1S 15130 (Part 2) :2002 Natural gas -- Determination of composition with Mirwd uncertainty by gas ctwomatography: Part 2 Measuring-system charactwistics and statistics fur data treatment Degree 0/ Equivalence Identicai Natural gas -- /s0 6974-1 :2000 Determination of composition with defined uncertainty by gas chromatography -- Part 1: Guidelines kx Mimed analysis 1S0 6974-2:2000 Determination of Mined uncertainty graphy -- Part 2: characteristics and treatment ISO 7504:7984 Vucabt~lary Natural gas -- composition with by gas chromatoMeasuring-system statistics for data Gas analysis -- do The Technics{ Committee responsible for the preparation of this standard wiil review the provisions 1S0 7504 and wili decide whe!ber they are acceptable for use in conjunction with this standard. of In repor!ing th~ rwults of a test or analysis made in accordance with this standard, if the final value, observed or calculated, is to be rounded off, it shall be done in accordance with IS 2:1960 `Rules for rounding off numericai valws (nwke@I'. Is UH30 ( Pm 31:2002 tSO 6974-3 ; 2000 lrdian Standard NATURAL GAS -- DETERMINATION OF COMPOSITION WITH DEFINED UNCERTAINTY BY GAS CHROMATOGRAPHY PART 3 I) ETERMINATKIN OF HY5M?OGENJ HELIUM, OXYGENJ NITROGEN, CARBON DH3XH2E AND HYDROCARBONS UP TO C* USING TWO PACKES) COLUMNS 1 scope This pan of 1S0 6974 d~scribes a gas cl-mmatoqraphic method for the quantitative determination of the content of uxy~en, nitqen, carbon dio~de and Cf ta C8 hydmca~!mw in natural gas samples using two MM.mL hycimpi, packed columm. This method k applicable to determinations made in omlhe processes or in the l~boratwy. it k q@caw to the ana@sk Of gases cunta~ning canstkuents within the mole fraction ranges given in Table 1 and cundemate, These ranges cio not represent the limits of dett3ctbr?, bW ttl% wFM do not contain any hydrocarbon Rnils within which the stated pw+%on of the method applies. AMuugh cm or more cumpcments in a sample may rwt be Cw3md present, me I-TNmod can Em m appmmle. This part of !S0 6974 k My applicable in conjunction with parts 1 and 2 of iSO 6974. 2 Normative references The following normative documents contain provisions which, through reference in this text, constittite provisions of this @ of HX) 69?4. For dated references, subseqwmi mnendrnenls to, or revisions of, any of these publications do nut apply. However, parties to a~reements based on W pari of ISO 6974 we encoumged W investigate the POSSWity of applying Ihe must recent ecli!ions of the normafive documents indicated below. Fur undated nNQmnces, the !a~est edition of the normative ductmxmt referred to applies, Members of ISO and IEC maintain B 15130 ( Part 3 ) :2002 1S0 6974-3:2000 of cc?mpcwwurl with defined Wm3tiair?ty by gas dW'7M@mphy 1S0 6974-2+ 11, Natural gas -- Determinafiofl Part 2: Measuring-system characterktics and statistics kv data treatment. -- 3 Principle Determination of nitrogen, carbon dioxide and hydrocarbons from Cl to C8 by gas chromatography using two chroma!ographic COMNK, A mcku!ar sieve 13X cuhmn coupled with a thermal conductivity defector (TCD) is used for the separation and detection of hydrogen, helium, oxygen and nitrogen, and a Porapak R column coupled with a TCD and a frame ionization detector (IW} in series is used for the separation and detection of nitrogen, and the results carbon dioxide and hydrocahms from +21M C3. The two analyses am canied out independently are combined. If uxygen k mm to be present at a mole fraction greater than 0,02 VUwhen measured using the molecular sieve column, then the nitrogen value shall be taken from the molecular sieve analysis. If the mole fraction of oxygen is less than 0,02 !% and aswninq thd hydrogen is absent from the gas sample, the ni~rogen vaiue can be taken from the Pmpak R wMysis. Quantitative results are achieved by determining the response of the TCD detector with reference-gas using relative response factors of the F+3 detector. mixtures and 4 Materials oxygen and nitrogen, (separation on For the determinaticm cd helium, hydrogen, 4*I Cokmm) consisting of the following. 4.1.1 Argon carrier mkcukir sieve 13X gas, > 99,99?& pure, free from oxygen and water. If the purity of Me gas is less than that specified, it is essential to check that h type d impurity present does not interfere with the analysis. Also, even if the carrier gases argon and/or helium fall within the specification, some of inkrfw~ with W analysis. Under these circumstances, the impurities present in the gases can nwwtheks appropriate purification is essenth31* 4.1.2 4,1.2.1 4=1*2=2 NOTE 1 Working-reference Gas mixtures Gas mixtures Take gas mixtures (WFWI), consisting of: containing containing helium and hydrogen with nitrogen or argon as the matrix gas, oxygen and nitrogen with argon as the matrix gas, care to prevent explosion of gas mixiwes. instrument, NOTE 2 In the case uf analysis using only om the matrix gas can be mpiwed by oxygen used for the daily calibration. WW Mmgen the WFIM with oxygen and nitrogen as cmpmmts and argon as as rnalrixgas. By WMWUR of helium to Me WRMthis gas could also W 1) To be published 2 Is 1513cu Part3] 1S0 6974.3:2000 :2002 4.2 4.2.1 4.2.2 For the deteminatkm column), consisting of nitrogen, carbon dioxide and hydrocarbons of the following= from ~~ to GE (separation on %rapak Helium carrier gas, Y 99,99 ?4 pure, free horn oxygen and water. gas mixtures containing: Working-reference gas mixtures (Wl+vl), consisting of muiti-cornponent nitrogen, carbon dioxide and hydrocarbons from Cl to C3 (optional to C4) An example of @ mmpos!tion of the wurking-+efermx gas mixture is given in Tab/e 2. of the working-reference gas mixture Table 2 -- Example of the composition Nitrogen MeN-w7e Carbon 6 80,5 dioxide 9 4 0,5 U,5 (Qptiunai) Ethw"w Propane r)-mtme 4,2,3 FID gases, consisting of >99,99 Y. pure, free from corrosive gases and urgank compounds; hydrogen, air, h-w from hy&OLXMXN7 impurities. Apparatus Es 15130 1S0 ( RN-t 3 ) :2002 6974-3:2000 temperature controller, corwishg d a linear programmer increase of 30 "Gknin over the specified range= b) flow regulator: capable of nmin!aining suitable carrier-gas suitable fur providing a rate of temperature flow rates. 5.1,1,2 hjwtion device, consisting o! a by-pass-type injector (gas-sampling valve) having an injection capaciky of 1 ml and capable of being heated to a temperature setting of 110 "G. The sample volume shall be reproducible such that successive runs agree within 1 ?'6for each component. 5.1.1.3 Columns, IWO with the same type of packing and with the same dinwnskms. The second column is normally used fur drift curnpensation during the temperature cumpwwted by mans of m ekxtmnic integrator, the second column k not necessary. CUlumns shall satisfy the following requirements a) me!ai tubingf having the Mowing chamc!erisiics: prugramme. If drift is nature: stainless steel, rmnlber 20 (AISI type 316), cleaned and degrmsed length; 1 WI diameter: 2 mm internal diameter (id.) fur Ihe clmmakqm@ form: a~~ro~riak radius: appropriate for the chmrnakqraph packing, Molecular sieve 13X, particle size from 150 pm b 1$0 pm (80 ASTM mesh to ?00 ASTM mesh); method of packing: my s~itable packing method providing uniform column packing; conditioning: overnight at approxhmatdy Nom problems. 350 "C under a flow of carefully dried carrier gas, above SWIIe Mjeetiundwices we unable to deal Thermal conductivity detector (TCD). with ternperatwes 250 "C and may cause mnditkming 5.1.?*4 5.1.2 For the determination of nitrogen, carbon dioxide and hydrocarbons from Cl to C8, equipped with the Mbwing 5.1.2.1 FKI. a) mkmn specific components and characteristics. Gas chromatography, suilable for dual-column application and equipped in series Wi!h a TCD and an own and temperature cuntmkr, CUrlSktkj & the temperature d W column to within k 0,5 `C over a temperature column oven, capab!e of nmWk@ range from 35 "C to 230 "C. NOTE To obtain may be necessary. -- a temperature Qf 35 "C an aCCeSSU~ w COOIing with liquid carbon tliuxkie or !iquki Mmgen temperature fwNruHf3r, consisting of a Iinear programmer suilabb increase of 15 `C/rein ov~r the specified range, for providing a rate uf temperature 4 IS 1S0 15130 6974+3 {Part 3):2002 :2000 b) fiow regulator, capabk of maintaining suitable carriw-gas flow rates. valve) having an injection Mjectiun device, consisting of a by-pass=type injector (gas-samp!ing 5,7 *2.2 capacity of 1 m! and capable of being heated to a tempem!ure setting of 110 W. S1 *2*3 Columns, two of Hw same type of packing and with the same dimensions. used for drift compensation during the temperature The sword cukmm is mmdy curnpensa{ed by means 01 an ekctrunk integrator, the second cokimn is nut necessary. a) metal tubing, nature: having W following characteristics: prugramrne, If drift k stainless steel, number 20 (AH type 316), cleaned and degreased -- -- -- length: 3 m diameter: 2 mm id. fmrn: appropriate radius: appropriate for the chrumatograph for the chmmatograph particle size from 150pm my suitable packing method b) !%rapak rmihod R packing, d packing: to 180 pm (80 ASTM mesh m 100 ASTM mesh); providing uniform column packing conditioning: overnight at approximately 5.1,2.4 -- -- Detecbrs, 230 W under a flow of carefully dried carrier gas having he following characteristics: hydrocarbons up to C3: thermal conductivity detector (FID) detector (TCD) for components for hydrocarbons including from CA to C8: flame ionization Hhane and propane can be detected by an FW2 if the mole fraction is less than 1 ?4. In either case, the time ccms!ant shall not be greater than 0,1 s. If C3 k used as reference component, it shall be detected by m FH3. -- ha T(2D and FKI detectors shall be connected in series 6 6.1 Procedure Gas chrunxitographic operating condition$ 6.1.1 For the determination conditions of helium, hychgenf oxygen and nitrogen Set ~h~ operating a) for the apparatus (5,1,1) as follows, Oven and column: initial temperature; -- 35 "C for 7 mh Mnperature rate: 30 "Wmin b 250 T is !s0 75130 (Pan3) :2002 6974-3:2000 set according to manufacturer's instructions carrier gas: argon 6* I4?.1 Gc Cmcmiom a] ovenand column: initial temperature: 37C for 3 nin -- temperature rate: 15 "Cknin to 200 "G h) -- carrier gas: helium T(XI i) Mnperatt.mx between 240 "C and 260% 6,3.2.2 Column stability check U-wk the baselb sJabNity of the column by means of blank runs. NCI individual peak shall originate from a constituent having a mole fraction exceeding 0,04 $%. If larger peaks a seen, repeat blank runs until satisfactory. H necessary, prepare new columns, preferably from a different batch RNapak R. 6 IS 15130 (Part3) :2002 so 6974-3:2000 NOTE 2 Baseline stability may be checked as follows: a) b) c) d) raise the mm~ to the final te~pwa!ure to cl~ar any accumulated COOI to the Mal injwt a calibration con!amina~bn; ternpera[ure; gas mixture containing a low mole fraclkm of bu{ane and s~ati the temperature programme; at the end of the calibration gas run, cool 10 the initial temperature, Perkmm a blank run by injecting carrier gas in place of a Sanple and start the @npemhm pwgwnme; 6.2 Performance requirements 6.2=1 Resolution efficiency Assess the peak resolution in accordance with ISU 7504 Table 3 -- Required peak resolution Component 1 m component Heh'n 2 Resolution Hydrogen 0,1@ IEM} 62=1.2 Purapak R cuhmm The height of the va!ley between the 2-metl@!NJtane and pen!ane peaks above the baseline shall be m greater than 10 % of the height of the larger peak under the operating conditions following injection of a sample. If this criterion is not me{, condition the packing for a longer period or prepare a new column. 6.2.2 Response ~espunse characteristics Dehxrnine W Once a year. fur each o! the gases determined in accordance with iSO 6974-2 a! least 6.2,3 Relative response factor VW 1S0 6974-2. Determine the relative response factors in accordance B /s0 15130 ( Part 3 ) :2002 6974-3:2000 63.1 ChNhe d W? maly$k 6*3.2 Esthnahn d Mw3r mmpment$ 7 Expression of results 7.1 *I NMe fractions Refer to Km 6974"1 * we = 78 ­ ---%@ x~2 21 In equation (1), it h ars.med thal the TCD wspmses for N2 and 02am eqwd. (2) h equation (2) R iS assumed that the TCD mponses for N2 and 02 an? equal, /l k thetotal TwTlkr d Cm-nponei-its; determined separately on both the II­Z is W total numbw of components except cwygen and Mrogenl molecular sieve 13X and Porapak R column. Fkfw k) MI 6974-2. see annex B for typical precision WEST E 1s0 q5130 ( I%M%3 ) :2002 6974-3:2000 AmImc A (informative) Singk-mm gasudmmatographic system consisting of two columns Both ana!y-ticd columns are placed in a single culumn oven and provided with a linear temperature programmer capable of obtaining a rate of temperature increase of 30 "Chin over Ihe specified range. A moiecu!ar sieve 13X cokmm is used fur the determination of helium, hydrogen, oxygen. The detection of these cm-npunen!s is carried out by TCD, The gas sample is injected using a by-pass-type injector with an injection capacity of 1 mL Flow regulators are used to give suitable argon gas-flow rates. A Purapak R column is used fur the determination of nitrogen, carbon dioxide, methane to normal Qctane. The detection is carried out by TCD in series with an FD The gas sample is injected using a by-pass-type injector (gas sampling valve) with an injection capacity of I ml. Flow regulators are used to give suitable helium gas flow rates. The ccmfigumtkm d such a chmmtugraphie Table Ad -- Detmminaliurl system isgiven inTable of A.1, system Configuration 1' ~ ! ?Wtrogm, Helium, hydrogen, oxygen the chromatographic carbon di=ide! methane to normal octane Mm-ml Packing Length Internal diameter ASTM mesh size Nktd tubing Carrier gas w: ktectur njection device Molecular sieve 13X 80 to 100 stainless steel Argon; 30 ml/min w TCD * 80 to 100 stainless sled Helium; 30 rnlhmin TCD and FID Capacity Valve temperature "temperature setting Initial temperature Initial time Temperature rate 1 ml m Ilo"c 40 "c 12 mitl 15 `Chin 200 "G 30 Ml 40 `c 12 min 15 "C/rein 200 Final temperature `c Final tkne 30 min Is 15130 ( PW3 ISO 6974-3:2000 ) :2002 start 11 IS fso 15?30[Part 6974-3:2000 3):2002 Nitrogen (oxygm) Methane Carlxm dioxide Emma Necl@fltane I=kptam ? ( 12 octane Figure A2 -- Typical chrormtogrwn of nitrogen (QXygen)$ carbon dioxide and hydrocarbons from (21 w (28 using a Porapak R coiumn E 15130 ( Part 3 ) :2002 1s0 6974-3:2000 Annex (h7f0rm~tive) B Typical precision values Typical values for repea!abili!y and reproducibility, lSO/K 158EC 2 in Udober 1986 with participa!km commercial laboratories from Be!@m, Gewnany, which have been assessed in an interkboratory test project of of gas-producing, gas-supplying, gas-shipping companies and keland, Nmvay, the Netherlands and the UK are given in Table B.1 -- Repaatatility ~ole fraction and reproducibility Repeatability of measurement results Reproducibility Absolute mule fraction ("/0) 0,0Q3 0,1 CX